Question: Solve for $x$ : $8\sqrt{x} - 9 = 10\sqrt{x} + 7$
Solution: Subtract $8\sqrt{x}$ from both sides: $(8\sqrt{x} - 9) - 8\sqrt{x} = (10\sqrt{x} + 7) - 8\sqrt{x}$ $-9 = 2\sqrt{x} + 7$ Subtract $7$ from both sides: $-9 - 7 = (2\sqrt{x} + 7) - 7$ $-16 = 2\sqrt{x}$ Divide both sides by $2$ $\frac{-16}{2} = \frac{2\sqrt{x}}{2}$ Simplify. $-8 = \sqrt{x}$ The principal root of a number cannot be negative. So, there is no solution.